New water pump impeller Honda 150

Alyssa Jean

New member
After changing out a worn out impeller on my Honda 50 I thought I should do some preventive maintenance on the 150. It has about 650 hours on it. Dropped the lower unit today with a rebuild kit in hand and found the original impeller to look practically new. Replaced it and have the old one for a back up.
Just thought some of you with 135/150s might find it interesting.
 
Anna Leigh":2unbhae8 said:
After changing out a worn out impeller on my Honda 50 I thought I should do some preventive maintenance on the 150. It has about 650 hours on it. Dropped the lower unit today with a rebuild kit in hand and found the original impeller to look practically new. Replaced it and have the old one for a back up.
Just thought some of you with 135/150s might find it interesting.

650 hours on the original impeller?!?!?

Wow!

I would not save it but that is impressive!
 
David,

...yea, pretty impressive. From my experience and reading, impellors in modern OBs seem to be very long-lived.

But at the same time, one of the items that sometimes becomes an issue is corrosion in the driveshaft splines. These splines and associated bolts must be lubed from time to time, or (I hear...) they can be Very difficult to remove.

Did your lower unit come off easily?

Best,
Casey
 
I did have to use a torch on two of them. Heated the outside of the area that the bolt screwed into. There are 7 14 mm bolts. I was afraid that I might blister the paint, but it didn't leave a mark. I used a liquid non hardening gasket material on the bolts when I put them back to keep out any salt water and corrosion. The spline on the main shaft needed more grease and I also added some to the spline on the shift shaft. n Leaving the throttle in gear while you do it helps in being able to slide the slines back together easier.
 
Spent last weekend working on changing out the impellers on our twin Honda 40's which still had the originals with close to 1200 hours. Nine out of the ten bolts holding the lower unit came out easy. The tenth even with heat broke the head off. Tried drilling and removal with an easy out and it broke off in the bolt. Couldn't get the hardened easy out "out", so had friend weld to top of the bolt and with heat still no go. Worked on that and drilling till damage was done to extension case, so then ordered new extension case. No problem with shaft splines either corrosion or removal, Casey and the very flexible rubber pump had zero noticeable wear. Infact only noticeable wear was in the inside of the lower pump case. The replacement kits had everything else in them that could possible be worn or lost in the replacement process, but the lower pump case, so had to order two of those to go with the extension case. Think both impellers could have made several more hundred hours, but like Casey said and David did, those bolts need protection.

Now that I see without bolts breaking, changing impellers is a very easy job. Think I will do it every two years. Impeller kits through http://www.boats.net/parts/search/Honda ... parts.html are only $18. On the other hand the extension case was $306.

Casey----as per the emails I did have an appointment with EQ to do the impeller work. Decided to attempt myself first.

Jay
 
RE: stuck lower unit bolts.

When I was an outboard mechanic, I heated the case until the paint was just smoking before trying a stuck bolt. We used a MAP gas torch to get more heat into the case faster. If using MAP gas, be careful as MAP gets hot enough to melt the case.

Burning paint is a good indicator of hot enough, but not so hot as to melt aluminium.

Repainting is cheaper than new cases!!

To prevent stuck bolts, new motors should have the bolts removed, one at a time and the bolts coated with non-hardening gasket sealer, or even just grease. Be sure to use a torque wrench when reassembling.
 
[This post wound up on the wrong thread the first time, so I am copying it to this thread.]

David - you mentioned leaving the "throttle" on ... I assume you meant leaving the motor in gear(?) to facilitate aligning the shaft?

Some motor instructions say to put the control in Forward and some in Neutral.

It depends on what has to be done to disconnect the shift rod when removing the lower unit.

If shifting to forward without the motor running you may have to rotate the prop some to align the shift dog in the transmission. If the shifter doesn't go into forward easily, try rotating or rocking the prop some. For safety, remove the key or disconnect the battery first.

It helps to have the shop manual to know what to do.
 
Frequent Sea (CD-25/Honda 130) received a new impeller (and more... much more) this spring after 3 years and over 500 hours. The old impeller looked new.

The downside of this story is that the gear plate behind the prop was so corroded from electrolysis that it actually appeared to be welded on the lower unit. Could not remove it so we wound up with a new lower unit. Well, the foot, anyway.

The upside is that we have a new lower unit that has not seen salt water.

Any one else had a similar experience?
 
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